In the spring of Genroku 14 (1701), Oishi Kuranosuke (Tamura Masakazu), the chief retainer of the Asano family in Ako domain is shocked to learn that his feudal lord,
Asano Takumi-no-kami Naganori (Tamayama Tetsuji), had stabbed Kira Kozukenosuke Yoshinaka (Nishida Toshiyuki), the master of ceremonies, at Edo castle.
Lord Asano was ordered to commit ritual suicide and the Ako clan abolished. Facing up to the gravity of this unfair ruling,
since only one party was being punished instead of both as would be usual, Oishi decides to lead the loyal former retainers in an attack on
Lord Kira so that he could take Kira�s head to his lord�s gravesite so that Lord Asano could finally rest in peace.